Extract as Numbers from a String to Calculate

The above data is basically pack sizes of bottles in a case. What it means is in case of "6X75ML" there are 6 bottles of 75CL (Centi liters) liquid each. For "6X2X75ML" which is basically a promotion pack has 6X2 = 12 bottles of 75ML (Milli liters) in a case.
I need to find the volume in liters available in each case:
e.g -

I have the below code helping me to find the quantity of bottles in a case

Working:
strplit breaks up the vector along "X". The resulting list is fed to sapply which the performs an operation on all but the final element of each vector in the list. The operation is to transform the elements into numeric s and the multiply them. The final element is dropped using head(x, -1).

I am not able to find a way around the an efficient way to split the last element to get the volume.